For larger civil or military aircraft it is conventional practice for the aircraft to have a single landing gear assembly located in the nose of the aircraft and a matched pair of landing gear assemblies located on either side of the aircraft in the proximity of the wing roots. The latter landing gear is generally termed the main landing gear assembly. It is conventional practice for both the nose landing gear assembly and main landing gear assembly to be arranged to be movable between a deployed position and a stowed position.
When the main landing gear is in the deployed, down, position it is beneficial for the distance between the pair of landing gear assemblies (the “track”) to be as wide as possible, since this maximises the stability of the aircraft on the ground during taxiing and runway manoeuvres. A well known way to achieve a wide track for the main landing gear is to mount each main landing gear assembly in each of the respective wings and to arrange for the main landing gear assemblies to retract to their stowed positions within the wing body and in some cases also partially within the fuselage body. However, for large aircraft, such as a commercial passenger airliners or freight aircraft, this results in relatively large loadings being transferred from the main landing gear assemblies into the wing structures. This requires the wing structures themselves to often be larger and heavier to carry these loads than would otherwise be required purely for the aerodynamic loading of the wing. Apart from the undesirable increase in weight, the increased wing structures also reduces the amount of space available within the wing structure for use in packaging wing service actuator systems (e.g. flaps), electrical systems, fuel tanks and ultimately space to stow the landing gear itself.
Another arrangement for the main landing gear that avoids placing large loads through the wing structures is the well known alternative of using body mounted landing gear, in which the main landing gear assemblies are mounted within the fuselage of the aircraft and are arranged to be stowed also within the aircraft fuselage. However, in order to maximise the landing gear track for body mounted landing gear assemblies it is known to use cantilevered main landing gear assemblies that position the actual wheels of the landing gear towards, if not beyond, the far extremities of the aircraft fuselage and with the wheels of the landing gear assemblies being further apart than the points at which the landing gear assembly is pivotably connected to the fuselage. As a corollary to this, such arrangements of main landing gear tend not to be capable of being housed in their stowed position completely within the nominal outline of the main fuselage and require a fuselage belly fairing, which is an enlarged area of the lower part of the fuselage, to enclose the landing gear in the stowed position. For larger belly fairings this can be detrimental to the overall aerodynamics of the aircraft, thus reducing the aircraft's theoretical performance. Additionally, the large belly fairings give rise to relatively large landing gear bay doors that must be arranged to fold out of the way when the landing gear is deployed. The large landing bay doors can limit the size of the movable wing surfaces closer to the junction between the wing and fuselage, again reducing the theoretical aerodynamic performance of the aircraft. In addition, since the landing gear assembly is stowed within the aircraft fuselage, this space cannot be used for other purposes, such as cargo stowage.
The main landing gear assembly arrangement of the present invention seeks to at least mitigate some of these problems.